The following data give the difference between actual arrival time and the scheduled arrival time for the 12 monthly flights that someone made into his/her resident city during the last year (positive...

The following data give the difference between actual arrival time and the scheduled arrival time for the 12 monthly flights that someone made into his/her resident city during the last year (positive values indicate the number of minutes the flight was late). The traveler always used the same airline and was scheduled to arrive at the same time on the last Wednesday of the month.

(a) Give conclusions if a flight was considered ‘‘on time’’ when it arrived within 20 minutes. (b) Give S4 / IEE considerations.